Question

срочно. решите пожалуйста алгебру.

Answer 1

$frac{10}{ {a}^{2} - 4} - frac{3}{a - 2} + frac{4}{a + 2} = frac{10}{(a - 2)(a + 2)} - frac{3(a + 2)}{(a - 2)(a + 2)} + frac{4(a - 2)}{(a - 2)(a + 2)} = frac{10 - (3a + 6) + 4a - 8}{(a - 2)(a + 2) } = frac{10 - 3a - 6 + 4a - 8}{(a - 2)(a + 2)} = frac{a - 4}{(a - 2)(a + 2)} = frac{a - 4}{ {a}^{2} - 4 }$

$( frac{a}{a - b} - frac{a}{a + b} ) times frac{a - b}{ab} = ( frac{a(a + b)}{(a - b)(a + b)} - frac{a(a - b)}{(a - b)(a + b)} ) times frac{a - b}{ab} = frac{ {a}^{2} + ab - {a}^{2} + ab }{(a - b)(a + b)} times frac{a - b}{ab} = frac{2ab times (a - b)}{(a - b)(a + b) times ab} = frac{2}{a + b}$

$frac{2c}{c - 3} - frac{ {c}^{2} + c}{4} div frac{c + 1}{8} = frac{2c}{c - 3} - frac{ {c}^{2} + c }{4} times frac{8}{c + 1} = frac{2c}{c - 3} - frac{c(c + 1) times 8}{4 times (c + 1)} = frac{2c}{c - 3} - frac{2c}{1} = frac{2c - 2c(c - 3)}{c - 3} = frac{2c - 2 {c}^{2} + 6c}{c - 3} = frac{ - 2 {c}^{2} + 8c }{c - 3}$